[U-Boot-Users] How to change MPU frequency in U-Boot?

[phAntOm yAng]

Dear All:

My platform and environment are U-Boot 1.1.3+Linux 2.6.14-omap1 on omap5912osk.

I try to change the value of MPU MHz, xtal MHz, dpll1 MHz.
After reading the source code, I found two informations:

1)In u-boot-1.1.3/board/omap5912osk/platform.S

VAL_ARM_CKCTL:
        .word 0x3000
VAL_DPLL1_CTL:
        .word 0x2830

2)in linux-2.6.14/arch/arm/mach-omap1/clock.h

/*-------------------------------------------------------------------------
 * Omap1 MPU rate table
 *-------------------------------------------------------------------------*/
static struct mpu_rate rate_table[] = {
	/* MPU MHz, xtal MHz, dpll1 MHz, CKCTL, DPLL_CTL
	 * NOTE: Comment order here is different from bits in CKCTL value:
	 * armdiv, dspdiv, dspmmu, tcdiv, perdiv, lcddiv
	 */
#if defined(CONFIG_OMAP_ARM_192MHZ)
	{ 192000000, 19200000, 192000000, 0x050f, 0x2510 }, /* 1/1/2/2/8/8 */
	{ 192000000, 12000000, 192000000, 0x050f, 0x2810 }, /* 1/1/2/2/8/8 */
	{  96000000, 12000000, 192000000, 0x055f, 0x2810 }, /* 2/2/2/2/8/8 */
	{  48000000, 12000000, 192000000, 0x0baf, 0x2810 }, /* 4/4/4/8/8/8 */
	{  24000000, 12000000, 192000000, 0x0fff, 0x2810 }, /* 8/8/8/8/8/8 */
#endif
#if defined(CONFIG_OMAP_ARM_168MHZ)
	{ 168000000, 12000000, 168000000, 0x010f, 0x2710 }, /* 1/1/1/2/8/8 */
#endif
#if defined(CONFIG_OMAP_ARM_120MHZ)
	{ 120000000, 12000000, 120000000, 0x010a, 0x2510 }, /* 1/1/1/2/4/4 */
#endif
#if defined(CONFIG_OMAP_ARM_60MHZ)
	{  60000000, 12000000,  60000000, 0x0005, 0x2290 }, /* 1/1/1/1/2/2 */
#endif
#if defined(CONFIG_OMAP_ARM_30MHZ)
	{  30000000, 12000000,  60000000, 0x0555, 0x2290 }, /* 2/2/2/2/2/2 */
#endif
	{ 0, 0, 0, 0, 0 },
};

But I can't find a relationship between these informations.

And are VAL_ARM_CKCTL and VAL_DPLL1_CTL the key value? 

Thanks,
phantom yang



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